1 /*
2 * Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "interpreter/interpreter.hpp"
28 #include "interpreter/oopMapCache.hpp"
29 #include "jvmtifiles/jvmtiEnv.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "oops/instanceKlass.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "prims/jvmtiAgentThread.hpp"
34 #include "prims/jvmtiEventController.inline.hpp"
35 #include "prims/jvmtiImpl.hpp"
36 #include "prims/jvmtiRedefineClasses.hpp"
37 #include "runtime/atomic.inline.hpp"
38 #include "runtime/deoptimization.hpp"
39 #include "runtime/handles.hpp"
40 #include "runtime/handles.inline.hpp"
41 #include "runtime/interfaceSupport.hpp"
42 #include "runtime/javaCalls.hpp"
43 #include "runtime/os.hpp"
44 #include "runtime/serviceThread.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/thread.inline.hpp"
47 #include "runtime/vframe.hpp"
48 #include "runtime/vframe_hp.hpp"
49 #include "runtime/vm_operations.hpp"
50 #include "utilities/exceptions.hpp"
51
52 //
53 // class JvmtiAgentThread
54 //
55 // JavaThread used to wrap a thread started by an agent
56 // using the JVMTI method RunAgentThread.
57 //
58
59 JvmtiAgentThread::JvmtiAgentThread(JvmtiEnv* env, jvmtiStartFunction start_fn, const void *start_arg)
60 : JavaThread(start_function_wrapper) {
61 _env = env;
62 _start_fn = start_fn;
63 _start_arg = start_arg;
64 }
65
66 void
67 JvmtiAgentThread::start_function_wrapper(JavaThread *thread, TRAPS) {
68 // It is expected that any Agent threads will be created as
69 // Java Threads. If this is the case, notification of the creation
70 // of the thread is given in JavaThread::thread_main().
71 assert(thread->is_Java_thread(), "debugger thread should be a Java Thread");
72 assert(thread == JavaThread::current(), "sanity check");
73
74 JvmtiAgentThread *dthread = (JvmtiAgentThread *)thread;
75 dthread->call_start_function();
76 }
77
78 void
79 JvmtiAgentThread::call_start_function() {
80 ThreadToNativeFromVM transition(this);
81 _start_fn(_env->jvmti_external(), jni_environment(), (void*)_start_arg);
82 }
83
84
85 //
86 // class GrowableCache - private methods
87 //
88
89 void GrowableCache::recache() {
90 int len = _elements->length();
91
92 FREE_C_HEAP_ARRAY(address, _cache);
93 _cache = NEW_C_HEAP_ARRAY(address,len+1, mtInternal);
94
95 for (int i=0; i<len; i++) {
96 _cache[i] = _elements->at(i)->getCacheValue();
97 //
98 // The cache entry has gone bad. Without a valid frame pointer
99 // value, the entry is useless so we simply delete it in product
100 // mode. The call to remove() will rebuild the cache again
101 // without the bad entry.
102 //
103 if (_cache[i] == NULL) {
104 assert(false, "cannot recache NULL elements");
105 remove(i);
106 return;
107 }
108 }
109 _cache[len] = NULL;
110
111 _listener_fun(_this_obj,_cache);
112 }
113
114 bool GrowableCache::equals(void* v, GrowableElement *e2) {
115 GrowableElement *e1 = (GrowableElement *) v;
116 assert(e1 != NULL, "e1 != NULL");
117 assert(e2 != NULL, "e2 != NULL");
118
119 return e1->equals(e2);
120 }
121
122 //
123 // class GrowableCache - public methods
124 //
125
126 GrowableCache::GrowableCache() {
127 _this_obj = NULL;
128 _listener_fun = NULL;
129 _elements = NULL;
130 _cache = NULL;
131 }
132
133 GrowableCache::~GrowableCache() {
134 clear();
135 delete _elements;
136 FREE_C_HEAP_ARRAY(address, _cache);
137 }
138
139 void GrowableCache::initialize(void *this_obj, void listener_fun(void *, address*) ) {
140 _this_obj = this_obj;
141 _listener_fun = listener_fun;
142 _elements = new (ResourceObj::C_HEAP, mtInternal) GrowableArray<GrowableElement*>(5,true);
143 recache();
144 }
145
146 // number of elements in the collection
147 int GrowableCache::length() {
148 return _elements->length();
149 }
150
151 // get the value of the index element in the collection
152 GrowableElement* GrowableCache::at(int index) {
153 GrowableElement *e = (GrowableElement *) _elements->at(index);
154 assert(e != NULL, "e != NULL");
155 return e;
156 }
157
158 int GrowableCache::find(GrowableElement* e) {
159 return _elements->find(e, GrowableCache::equals);
160 }
161
162 // append a copy of the element to the end of the collection
163 void GrowableCache::append(GrowableElement* e) {
164 GrowableElement *new_e = e->clone();
165 _elements->append(new_e);
166 recache();
167 }
168
169 // insert a copy of the element using lessthan()
170 void GrowableCache::insert(GrowableElement* e) {
171 GrowableElement *new_e = e->clone();
172 _elements->append(new_e);
173
174 int n = length()-2;
175 for (int i=n; i>=0; i--) {
176 GrowableElement *e1 = _elements->at(i);
177 GrowableElement *e2 = _elements->at(i+1);
178 if (e2->lessThan(e1)) {
179 _elements->at_put(i+1, e1);
180 _elements->at_put(i, e2);
181 }
182 }
183
184 recache();
185 }
186
187 // remove the element at index
188 void GrowableCache::remove (int index) {
189 GrowableElement *e = _elements->at(index);
190 assert(e != NULL, "e != NULL");
191 _elements->remove(e);
192 delete e;
193 recache();
194 }
195
196 // clear out all elements, release all heap space and
197 // let our listener know that things have changed.
198 void GrowableCache::clear() {
199 int len = _elements->length();
200 for (int i=0; i<len; i++) {
201 delete _elements->at(i);
202 }
203 _elements->clear();
204 recache();
205 }
206
207 void GrowableCache::oops_do(OopClosure* f) {
208 int len = _elements->length();
209 for (int i=0; i<len; i++) {
210 GrowableElement *e = _elements->at(i);
211 e->oops_do(f);
212 }
213 }
214
215 void GrowableCache::metadata_do(void f(Metadata*)) {
216 int len = _elements->length();
217 for (int i=0; i<len; i++) {
218 GrowableElement *e = _elements->at(i);
219 e->metadata_do(f);
220 }
221 }
222
223 void GrowableCache::gc_epilogue() {
224 int len = _elements->length();
225 for (int i=0; i<len; i++) {
226 _cache[i] = _elements->at(i)->getCacheValue();
227 }
228 }
229
230 //
231 // class JvmtiBreakpoint
232 //
233
234 JvmtiBreakpoint::JvmtiBreakpoint() {
235 _method = NULL;
236 _bci = 0;
237 _class_holder = NULL;
238 }
239
240 JvmtiBreakpoint::JvmtiBreakpoint(Method* m_method, jlocation location) {
241 _method = m_method;
242 _class_holder = _method->method_holder()->klass_holder();
243 #ifdef CHECK_UNHANDLED_OOPS
244 // _class_holder can't be wrapped in a Handle, because JvmtiBreakpoints are
245 // sometimes allocated on the heap.
246 //
247 // The code handling JvmtiBreakpoints allocated on the stack can't be
248 // interrupted by a GC until _class_holder is reachable by the GC via the
249 // oops_do method.
250 Thread::current()->allow_unhandled_oop(&_class_holder);
251 #endif // CHECK_UNHANDLED_OOPS
252 assert(_method != NULL, "_method != NULL");
253 _bci = (int) location;
254 assert(_bci >= 0, "_bci >= 0");
255 }
256
257 void JvmtiBreakpoint::copy(JvmtiBreakpoint& bp) {
258 _method = bp._method;
259 _bci = bp._bci;
260 _class_holder = bp._class_holder;
261 }
262
263 bool JvmtiBreakpoint::lessThan(JvmtiBreakpoint& bp) {
264 Unimplemented();
265 return false;
266 }
267
268 bool JvmtiBreakpoint::equals(JvmtiBreakpoint& bp) {
269 return _method == bp._method
270 && _bci == bp._bci;
271 }
272
273 bool JvmtiBreakpoint::is_valid() {
274 // class loader can be NULL
275 return _method != NULL &&
276 _bci >= 0;
277 }
278
279 address JvmtiBreakpoint::getBcp() {
280 return _method->bcp_from(_bci);
281 }
282
283 void JvmtiBreakpoint::each_method_version_do(method_action meth_act) {
284 ((Method*)_method->*meth_act)(_bci);
285
286 // add/remove breakpoint to/from versions of the method that are EMCP.
287 Thread *thread = Thread::current();
288 instanceKlassHandle ikh = instanceKlassHandle(thread, _method->method_holder());
289 Symbol* m_name = _method->name();
290 Symbol* m_signature = _method->signature();
291
292 // search previous versions if they exist
293 for (InstanceKlass* pv_node = ikh->previous_versions();
294 pv_node != NULL;
295 pv_node = pv_node->previous_versions()) {
296 Array<Method*>* methods = pv_node->methods();
297
298 for (int i = methods->length() - 1; i >= 0; i--) {
299 Method* method = methods->at(i);
300 // Only set breakpoints in running EMCP methods.
301 if (method->is_running_emcp() &&
302 method->name() == m_name &&
303 method->signature() == m_signature) {
304 RC_TRACE(0x00000800, ("%sing breakpoint in %s(%s)",
305 meth_act == &Method::set_breakpoint ? "sett" : "clear",
306 method->name()->as_C_string(),
307 method->signature()->as_C_string()));
308
309 (method->*meth_act)(_bci);
310 break;
311 }
312 }
313 }
314 }
315
316 void JvmtiBreakpoint::set() {
317 each_method_version_do(&Method::set_breakpoint);
318 }
319
320 void JvmtiBreakpoint::clear() {
321 each_method_version_do(&Method::clear_breakpoint);
322 }
323
324 void JvmtiBreakpoint::print() {
325 #ifndef PRODUCT
326 const char *class_name = (_method == NULL) ? "NULL" : _method->klass_name()->as_C_string();
327 const char *method_name = (_method == NULL) ? "NULL" : _method->name()->as_C_string();
328
329 tty->print("Breakpoint(%s,%s,%d,%p)",class_name, method_name, _bci, getBcp());
330 #endif
331 }
332
333
334 //
335 // class VM_ChangeBreakpoints
336 //
337 // Modify the Breakpoints data structure at a safepoint
338 //
339
340 void VM_ChangeBreakpoints::doit() {
341 switch (_operation) {
342 case SET_BREAKPOINT:
343 _breakpoints->set_at_safepoint(*_bp);
344 break;
345 case CLEAR_BREAKPOINT:
346 _breakpoints->clear_at_safepoint(*_bp);
347 break;
348 default:
349 assert(false, "Unknown operation");
350 }
351 }
352
353 void VM_ChangeBreakpoints::oops_do(OopClosure* f) {
354 // The JvmtiBreakpoints in _breakpoints will be visited via
355 // JvmtiExport::oops_do.
356 if (_bp != NULL) {
357 _bp->oops_do(f);
358 }
359 }
360
361 void VM_ChangeBreakpoints::metadata_do(void f(Metadata*)) {
362 // Walk metadata in breakpoints to keep from being deallocated with RedefineClasses
363 if (_bp != NULL) {
364 _bp->metadata_do(f);
365 }
366 }
367
368 //
369 // class JvmtiBreakpoints
370 //
371 // a JVMTI internal collection of JvmtiBreakpoint
372 //
373
374 JvmtiBreakpoints::JvmtiBreakpoints(void listener_fun(void *,address *)) {
375 _bps.initialize(this,listener_fun);
376 }
377
378 JvmtiBreakpoints:: ~JvmtiBreakpoints() {}
379
380 void JvmtiBreakpoints::oops_do(OopClosure* f) {
381 _bps.oops_do(f);
382 }
383
384 void JvmtiBreakpoints::metadata_do(void f(Metadata*)) {
385 _bps.metadata_do(f);
386 }
387
388 void JvmtiBreakpoints::gc_epilogue() {
389 _bps.gc_epilogue();
390 }
391
392 void JvmtiBreakpoints::print() {
393 #ifndef PRODUCT
394 ResourceMark rm;
395
396 int n = _bps.length();
397 for (int i=0; i<n; i++) {
398 JvmtiBreakpoint& bp = _bps.at(i);
399 tty->print("%d: ", i);
400 bp.print();
401 tty->cr();
402 }
403 #endif
404 }
405
406
407 void JvmtiBreakpoints::set_at_safepoint(JvmtiBreakpoint& bp) {
408 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
409
410 int i = _bps.find(bp);
411 if (i == -1) {
412 _bps.append(bp);
413 bp.set();
414 }
415 }
416
417 void JvmtiBreakpoints::clear_at_safepoint(JvmtiBreakpoint& bp) {
418 assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
419
420 int i = _bps.find(bp);
421 if (i != -1) {
422 _bps.remove(i);
423 bp.clear();
424 }
425 }
426
427 int JvmtiBreakpoints::length() { return _bps.length(); }
428
429 int JvmtiBreakpoints::set(JvmtiBreakpoint& bp) {
430 if ( _bps.find(bp) != -1) {
431 return JVMTI_ERROR_DUPLICATE;
432 }
433 VM_ChangeBreakpoints set_breakpoint(VM_ChangeBreakpoints::SET_BREAKPOINT, &bp);
434 VMThread::execute(&set_breakpoint);
435 return JVMTI_ERROR_NONE;
436 }
437
438 int JvmtiBreakpoints::clear(JvmtiBreakpoint& bp) {
439 if ( _bps.find(bp) == -1) {
440 return JVMTI_ERROR_NOT_FOUND;
441 }
442
443 VM_ChangeBreakpoints clear_breakpoint(VM_ChangeBreakpoints::CLEAR_BREAKPOINT, &bp);
444 VMThread::execute(&clear_breakpoint);
445 return JVMTI_ERROR_NONE;
446 }
447
448 void JvmtiBreakpoints::clearall_in_class_at_safepoint(Klass* klass) {
449 bool changed = true;
450 // We are going to run thru the list of bkpts
451 // and delete some. This deletion probably alters
452 // the list in some implementation defined way such
453 // that when we delete entry i, the next entry might
454 // no longer be at i+1. To be safe, each time we delete
455 // an entry, we'll just start again from the beginning.
456 // We'll stop when we make a pass thru the whole list without
457 // deleting anything.
458 while (changed) {
459 int len = _bps.length();
460 changed = false;
461 for (int i = 0; i < len; i++) {
462 JvmtiBreakpoint& bp = _bps.at(i);
463 if (bp.method()->method_holder() == klass) {
464 bp.clear();
465 _bps.remove(i);
466 // This changed 'i' so we have to start over.
467 changed = true;
468 break;
469 }
470 }
471 }
472 }
473
474 //
475 // class JvmtiCurrentBreakpoints
476 //
477
478 JvmtiBreakpoints *JvmtiCurrentBreakpoints::_jvmti_breakpoints = NULL;
479 address * JvmtiCurrentBreakpoints::_breakpoint_list = NULL;
480
481
482 JvmtiBreakpoints& JvmtiCurrentBreakpoints::get_jvmti_breakpoints() {
483 if (_jvmti_breakpoints != NULL) return (*_jvmti_breakpoints);
484 _jvmti_breakpoints = new JvmtiBreakpoints(listener_fun);
485 assert(_jvmti_breakpoints != NULL, "_jvmti_breakpoints != NULL");
486 return (*_jvmti_breakpoints);
487 }
488
489 void JvmtiCurrentBreakpoints::listener_fun(void *this_obj, address *cache) {
490 JvmtiBreakpoints *this_jvmti = (JvmtiBreakpoints *) this_obj;
491 assert(this_jvmti != NULL, "this_jvmti != NULL");
492
493 debug_only(int n = this_jvmti->length(););
494 assert(cache[n] == NULL, "cache must be NULL terminated");
495
496 set_breakpoint_list(cache);
497 }
498
499
500 void JvmtiCurrentBreakpoints::oops_do(OopClosure* f) {
501 if (_jvmti_breakpoints != NULL) {
502 _jvmti_breakpoints->oops_do(f);
503 }
504 }
505
506 void JvmtiCurrentBreakpoints::metadata_do(void f(Metadata*)) {
507 if (_jvmti_breakpoints != NULL) {
508 _jvmti_breakpoints->metadata_do(f);
509 }
510 }
511
512 void JvmtiCurrentBreakpoints::gc_epilogue() {
513 if (_jvmti_breakpoints != NULL) {
514 _jvmti_breakpoints->gc_epilogue();
515 }
516 }
517
518 ///////////////////////////////////////////////////////////////
519 //
520 // class VM_GetOrSetLocal
521 //
522
523 // Constructor for non-object getter
524 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type)
525 : _thread(thread)
526 , _calling_thread(NULL)
527 , _depth(depth)
528 , _index(index)
529 , _type(type)
530 , _set(false)
531 , _jvf(NULL)
532 , _result(JVMTI_ERROR_NONE)
533 {
534 }
535
536 // Constructor for object or non-object setter
537 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, jint depth, int index, BasicType type, jvalue value)
538 : _thread(thread)
539 , _calling_thread(NULL)
540 , _depth(depth)
541 , _index(index)
542 , _type(type)
543 , _value(value)
544 , _set(true)
545 , _jvf(NULL)
546 , _result(JVMTI_ERROR_NONE)
547 {
548 }
549
550 // Constructor for object getter
551 VM_GetOrSetLocal::VM_GetOrSetLocal(JavaThread* thread, JavaThread* calling_thread, jint depth, int index)
552 : _thread(thread)
553 , _calling_thread(calling_thread)
554 , _depth(depth)
555 , _index(index)
556 , _type(T_OBJECT)
557 , _set(false)
558 , _jvf(NULL)
559 , _result(JVMTI_ERROR_NONE)
560 {
561 }
562
563 vframe *VM_GetOrSetLocal::get_vframe() {
564 if (!_thread->has_last_Java_frame()) {
565 return NULL;
566 }
567 RegisterMap reg_map(_thread);
568 vframe *vf = _thread->last_java_vframe(®_map);
569 int d = 0;
570 while ((vf != NULL) && (d < _depth)) {
571 vf = vf->java_sender();
572 d++;
573 }
574 return vf;
575 }
576
577 javaVFrame *VM_GetOrSetLocal::get_java_vframe() {
578 vframe* vf = get_vframe();
579 if (vf == NULL) {
580 _result = JVMTI_ERROR_NO_MORE_FRAMES;
581 return NULL;
582 }
583 javaVFrame *jvf = (javaVFrame*)vf;
584
585 if (!vf->is_java_frame()) {
586 _result = JVMTI_ERROR_OPAQUE_FRAME;
587 return NULL;
588 }
589 return jvf;
590 }
591
592 // Check that the klass is assignable to a type with the given signature.
593 // Another solution could be to use the function Klass::is_subtype_of(type).
594 // But the type class can be forced to load/initialize eagerly in such a case.
595 // This may cause unexpected consequences like CFLH or class-init JVMTI events.
596 // It is better to avoid such a behavior.
597 bool VM_GetOrSetLocal::is_assignable(const char* ty_sign, Klass* klass, Thread* thread) {
598 assert(ty_sign != NULL, "type signature must not be NULL");
599 assert(thread != NULL, "thread must not be NULL");
600 assert(klass != NULL, "klass must not be NULL");
601
602 int len = (int) strlen(ty_sign);
603 if (ty_sign[0] == 'L' && ty_sign[len-1] == ';') { // Need pure class/interface name
604 ty_sign++;
605 len -= 2;
606 }
607 TempNewSymbol ty_sym = SymbolTable::new_symbol(ty_sign, len, thread);
608 if (klass->name() == ty_sym) {
609 return true;
610 }
611 // Compare primary supers
612 int super_depth = klass->super_depth();
613 int idx;
614 for (idx = 0; idx < super_depth; idx++) {
615 if (klass->primary_super_of_depth(idx)->name() == ty_sym) {
616 return true;
617 }
618 }
619 // Compare secondary supers
620 Array<Klass*>* sec_supers = klass->secondary_supers();
621 for (idx = 0; idx < sec_supers->length(); idx++) {
622 if (((Klass*) sec_supers->at(idx))->name() == ty_sym) {
623 return true;
624 }
625 }
626 return false;
627 }
628
629 // Checks error conditions:
630 // JVMTI_ERROR_INVALID_SLOT
631 // JVMTI_ERROR_TYPE_MISMATCH
632 // Returns: 'true' - everything is Ok, 'false' - error code
633
634 bool VM_GetOrSetLocal::check_slot_type(javaVFrame* jvf) {
635 Method* method_oop = jvf->method();
636 if (!method_oop->has_localvariable_table()) {
637 // Just to check index boundaries
638 jint extra_slot = (_type == T_LONG || _type == T_DOUBLE) ? 1 : 0;
639 if (_index < 0 || _index + extra_slot >= method_oop->max_locals()) {
640 _result = JVMTI_ERROR_INVALID_SLOT;
641 return false;
642 }
643 return true;
644 }
645
646 jint num_entries = method_oop->localvariable_table_length();
647 if (num_entries == 0) {
648 _result = JVMTI_ERROR_INVALID_SLOT;
649 return false; // There are no slots
650 }
651 int signature_idx = -1;
652 int vf_bci = jvf->bci();
653 LocalVariableTableElement* table = method_oop->localvariable_table_start();
654 for (int i = 0; i < num_entries; i++) {
655 int start_bci = table[i].start_bci;
656 int end_bci = start_bci + table[i].length;
657
658 // Here we assume that locations of LVT entries
659 // with the same slot number cannot be overlapped
660 if (_index == (jint) table[i].slot && start_bci <= vf_bci && vf_bci <= end_bci) {
661 signature_idx = (int) table[i].descriptor_cp_index;
662 break;
663 }
664 }
665 if (signature_idx == -1) {
666 _result = JVMTI_ERROR_INVALID_SLOT;
667 return false; // Incorrect slot index
668 }
669 Symbol* sign_sym = method_oop->constants()->symbol_at(signature_idx);
670 const char* signature = (const char *) sign_sym->as_utf8();
671 BasicType slot_type = char2type(signature[0]);
672
673 switch (slot_type) {
674 case T_BYTE:
675 case T_SHORT:
676 case T_CHAR:
677 case T_BOOLEAN:
678 slot_type = T_INT;
679 break;
680 case T_ARRAY:
681 slot_type = T_OBJECT;
682 break;
683 };
684 if (_type != slot_type) {
685 _result = JVMTI_ERROR_TYPE_MISMATCH;
686 return false;
687 }
688
689 jobject jobj = _value.l;
690 if (_set && slot_type == T_OBJECT && jobj != NULL) { // NULL reference is allowed
691 // Check that the jobject class matches the return type signature.
692 JavaThread* cur_thread = JavaThread::current();
693 HandleMark hm(cur_thread);
694
695 Handle obj = Handle(cur_thread, JNIHandles::resolve_external_guard(jobj));
696 NULL_CHECK(obj, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
697 KlassHandle ob_kh = KlassHandle(cur_thread, obj->klass());
698 NULL_CHECK(ob_kh, (_result = JVMTI_ERROR_INVALID_OBJECT, false));
699
700 if (!is_assignable(signature, ob_kh(), cur_thread)) {
701 _result = JVMTI_ERROR_TYPE_MISMATCH;
702 return false;
703 }
704 }
705 return true;
706 }
707
708 static bool can_be_deoptimized(vframe* vf) {
709 return (vf->is_compiled_frame() && vf->fr().can_be_deoptimized());
710 }
711
712 bool VM_GetOrSetLocal::doit_prologue() {
713 _jvf = get_java_vframe();
714 NULL_CHECK(_jvf, false);
715
716 if (_jvf->method()->is_native()) {
717 if (getting_receiver() && !_jvf->method()->is_static()) {
718 return true;
719 } else {
720 _result = JVMTI_ERROR_OPAQUE_FRAME;
721 return false;
722 }
723 }
724
725 if (!check_slot_type(_jvf)) {
726 return false;
727 }
728 return true;
729 }
730
731 void VM_GetOrSetLocal::doit() {
732 InterpreterOopMap oop_mask;
733 _jvf->method()->mask_for(_jvf->bci(), &oop_mask);
734 if (oop_mask.is_dead(_index)) {
735 // The local can be invalid and uninitialized in the scope of current bci
736 _result = JVMTI_ERROR_INVALID_SLOT;
737 return;
738 }
739 if (_set) {
740 // Force deoptimization of frame if compiled because it's
741 // possible the compiler emitted some locals as constant values,
742 // meaning they are not mutable.
743 if (can_be_deoptimized(_jvf)) {
744
745 // Schedule deoptimization so that eventually the local
746 // update will be written to an interpreter frame.
747 Deoptimization::deoptimize_frame(_jvf->thread(), _jvf->fr().id());
748
749 // Now store a new value for the local which will be applied
750 // once deoptimization occurs. Note however that while this
751 // write is deferred until deoptimization actually happens
752 // can vframe created after this point will have its locals
753 // reflecting this update so as far as anyone can see the
754 // write has already taken place.
755
756 // If we are updating an oop then get the oop from the handle
757 // since the handle will be long gone by the time the deopt
758 // happens. The oop stored in the deferred local will be
759 // gc'd on its own.
760 if (_type == T_OBJECT) {
761 _value.l = (jobject) (JNIHandles::resolve_external_guard(_value.l));
762 }
763 // Re-read the vframe so we can see that it is deoptimized
764 // [ Only need because of assert in update_local() ]
765 _jvf = get_java_vframe();
766 ((compiledVFrame*)_jvf)->update_local(_type, _index, _value);
767 return;
768 }
769 StackValueCollection *locals = _jvf->locals();
770 HandleMark hm;
771
772 switch (_type) {
773 case T_INT: locals->set_int_at (_index, _value.i); break;
774 case T_LONG: locals->set_long_at (_index, _value.j); break;
775 case T_FLOAT: locals->set_float_at (_index, _value.f); break;
776 case T_DOUBLE: locals->set_double_at(_index, _value.d); break;
777 case T_OBJECT: {
778 Handle ob_h(JNIHandles::resolve_external_guard(_value.l));
779 locals->set_obj_at (_index, ob_h);
780 break;
781 }
782 default: ShouldNotReachHere();
783 }
784 _jvf->set_locals(locals);
785 } else {
786 if (_jvf->method()->is_native() && _jvf->is_compiled_frame()) {
787 assert(getting_receiver(), "Can only get here when getting receiver");
788 oop receiver = _jvf->fr().get_native_receiver();
789 _value.l = JNIHandles::make_local(_calling_thread, receiver);
790 } else {
791 StackValueCollection *locals = _jvf->locals();
792
793 if (locals->at(_index)->type() == T_CONFLICT) {
794 memset(&_value, 0, sizeof(_value));
795 _value.l = NULL;
796 return;
797 }
798
799 switch (_type) {
800 case T_INT: _value.i = locals->int_at (_index); break;
801 case T_LONG: _value.j = locals->long_at (_index); break;
802 case T_FLOAT: _value.f = locals->float_at (_index); break;
803 case T_DOUBLE: _value.d = locals->double_at(_index); break;
804 case T_OBJECT: {
805 // Wrap the oop to be returned in a local JNI handle since
806 // oops_do() no longer applies after doit() is finished.
807 oop obj = locals->obj_at(_index)();
808 _value.l = JNIHandles::make_local(_calling_thread, obj);
809 break;
810 }
811 default: ShouldNotReachHere();
812 }
813 }
814 }
815 }
816
817
818 bool VM_GetOrSetLocal::allow_nested_vm_operations() const {
819 return true; // May need to deoptimize
820 }
821
822
823 VM_GetReceiver::VM_GetReceiver(
824 JavaThread* thread, JavaThread* caller_thread, jint depth)
825 : VM_GetOrSetLocal(thread, caller_thread, depth, 0) {}
826
827 /////////////////////////////////////////////////////////////////////////////////////////
828
829 //
830 // class JvmtiSuspendControl - see comments in jvmtiImpl.hpp
831 //
832
833 bool JvmtiSuspendControl::suspend(JavaThread *java_thread) {
834 // external suspend should have caught suspending a thread twice
835
836 // Immediate suspension required for JPDA back-end so JVMTI agent threads do
837 // not deadlock due to later suspension on transitions while holding
838 // raw monitors. Passing true causes the immediate suspension.
839 // java_suspend() will catch threads in the process of exiting
840 // and will ignore them.
841 java_thread->java_suspend();
842
843 // It would be nice to have the following assertion in all the time,
844 // but it is possible for a racing resume request to have resumed
845 // this thread right after we suspended it. Temporarily enable this
846 // assertion if you are chasing a different kind of bug.
847 //
848 // assert(java_lang_Thread::thread(java_thread->threadObj()) == NULL ||
849 // java_thread->is_being_ext_suspended(), "thread is not suspended");
850
851 if (java_lang_Thread::thread(java_thread->threadObj()) == NULL) {
852 // check again because we can get delayed in java_suspend():
853 // the thread is in process of exiting.
854 return false;
855 }
856
857 return true;
858 }
859
860 bool JvmtiSuspendControl::resume(JavaThread *java_thread) {
861 // external suspend should have caught resuming a thread twice
862 assert(java_thread->is_being_ext_suspended(), "thread should be suspended");
863
864 // resume thread
865 {
866 // must always grab Threads_lock, see JVM_SuspendThread
867 MutexLocker ml(Threads_lock);
868 java_thread->java_resume();
869 }
870
871 return true;
872 }
873
874
875 void JvmtiSuspendControl::print() {
876 #ifndef PRODUCT
877 MutexLocker mu(Threads_lock);
878 ResourceMark rm;
879
880 tty->print("Suspended Threads: [");
881 for (JavaThread *thread = Threads::first(); thread != NULL; thread = thread->next()) {
882 #ifdef JVMTI_TRACE
883 const char *name = JvmtiTrace::safe_get_thread_name(thread);
884 #else
885 const char *name = "";
886 #endif /*JVMTI_TRACE */
887 tty->print("%s(%c ", name, thread->is_being_ext_suspended() ? 'S' : '_');
888 if (!thread->has_last_Java_frame()) {
889 tty->print("no stack");
890 }
891 tty->print(") ");
892 }
893 tty->print_cr("]");
894 #endif
895 }
896
897 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event(
898 nmethod* nm) {
899 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD);
900 event._event_data.compiled_method_load = nm;
901 // Keep the nmethod alive until the ServiceThread can process
902 // this deferred event.
903 nmethodLocker::lock_nmethod(nm);
904 return event;
905 }
906
907 JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event(
908 nmethod* nm, jmethodID id, const void* code) {
909 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD);
910 event._event_data.compiled_method_unload.nm = nm;
911 event._event_data.compiled_method_unload.method_id = id;
912 event._event_data.compiled_method_unload.code_begin = code;
913 // Keep the nmethod alive until the ServiceThread can process
914 // this deferred event. This will keep the memory for the
915 // generated code from being reused too early. We pass
916 // zombie_ok == true here so that our nmethod that was just
917 // made into a zombie can be locked.
918 nmethodLocker::lock_nmethod(nm, true /* zombie_ok */);
919 return event;
920 }
921
922 JvmtiDeferredEvent JvmtiDeferredEvent::dynamic_code_generated_event(
923 const char* name, const void* code_begin, const void* code_end) {
924 JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_DYNAMIC_CODE_GENERATED);
925 // Need to make a copy of the name since we don't know how long
926 // the event poster will keep it around after we enqueue the
927 // deferred event and return. strdup() failure is handled in
928 // the post() routine below.
929 event._event_data.dynamic_code_generated.name = os::strdup(name);
930 event._event_data.dynamic_code_generated.code_begin = code_begin;
931 event._event_data.dynamic_code_generated.code_end = code_end;
932 return event;
933 }
934
935 void JvmtiDeferredEvent::post() {
936 assert(ServiceThread::is_service_thread(Thread::current()),
937 "Service thread must post enqueued events");
938 switch(_type) {
939 case TYPE_COMPILED_METHOD_LOAD: {
940 nmethod* nm = _event_data.compiled_method_load;
941 JvmtiExport::post_compiled_method_load(nm);
942 // done with the deferred event so unlock the nmethod
943 nmethodLocker::unlock_nmethod(nm);
944 break;
945 }
946 case TYPE_COMPILED_METHOD_UNLOAD: {
947 nmethod* nm = _event_data.compiled_method_unload.nm;
948 JvmtiExport::post_compiled_method_unload(
949 _event_data.compiled_method_unload.method_id,
950 _event_data.compiled_method_unload.code_begin);
951 // done with the deferred event so unlock the nmethod
952 nmethodLocker::unlock_nmethod(nm);
953 break;
954 }
955 case TYPE_DYNAMIC_CODE_GENERATED: {
956 JvmtiExport::post_dynamic_code_generated_internal(
957 // if strdup failed give the event a default name
958 (_event_data.dynamic_code_generated.name == NULL)
959 ? "unknown_code" : _event_data.dynamic_code_generated.name,
960 _event_data.dynamic_code_generated.code_begin,
961 _event_data.dynamic_code_generated.code_end);
962 if (_event_data.dynamic_code_generated.name != NULL) {
963 // release our copy
964 os::free((void *)_event_data.dynamic_code_generated.name);
965 }
966 break;
967 }
968 default:
969 ShouldNotReachHere();
970 }
971 }
972
973 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL;
974 JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL;
975
976 volatile JvmtiDeferredEventQueue::QueueNode*
977 JvmtiDeferredEventQueue::_pending_list = NULL;
978
979 bool JvmtiDeferredEventQueue::has_events() {
980 assert(Service_lock->owned_by_self(), "Must own Service_lock");
981 return _queue_head != NULL || _pending_list != NULL;
982 }
983
984 void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) {
985 assert(Service_lock->owned_by_self(), "Must own Service_lock");
986
987 process_pending_events();
988
989 // Events get added to the end of the queue (and are pulled off the front).
990 QueueNode* node = new QueueNode(event);
991 if (_queue_tail == NULL) {
992 _queue_tail = _queue_head = node;
993 } else {
994 assert(_queue_tail->next() == NULL, "Must be the last element in the list");
995 _queue_tail->set_next(node);
996 _queue_tail = node;
997 }
998
999 Service_lock->notify_all();
1000 assert((_queue_head == NULL) == (_queue_tail == NULL),
1001 "Inconsistent queue markers");
1002 }
1003
1004 JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() {
1005 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1006
1007 process_pending_events();
1008
1009 assert(_queue_head != NULL, "Nothing to dequeue");
1010
1011 if (_queue_head == NULL) {
1012 // Just in case this happens in product; it shouldn't but let's not crash
1013 return JvmtiDeferredEvent();
1014 }
1015
1016 QueueNode* node = _queue_head;
1017 _queue_head = _queue_head->next();
1018 if (_queue_head == NULL) {
1019 _queue_tail = NULL;
1020 }
1021
1022 assert((_queue_head == NULL) == (_queue_tail == NULL),
1023 "Inconsistent queue markers");
1024
1025 JvmtiDeferredEvent event = node->event();
1026 delete node;
1027 return event;
1028 }
1029
1030 void JvmtiDeferredEventQueue::add_pending_event(
1031 const JvmtiDeferredEvent& event) {
1032
1033 QueueNode* node = new QueueNode(event);
1034
1035 bool success = false;
1036 QueueNode* prev_value = (QueueNode*)_pending_list;
1037 do {
1038 node->set_next(prev_value);
1039 prev_value = (QueueNode*)Atomic::cmpxchg_ptr(
1040 (void*)node, (volatile void*)&_pending_list, (void*)node->next());
1041 } while (prev_value != node->next());
1042 }
1043
1044 // This method transfers any events that were added by someone NOT holding
1045 // the lock into the mainline queue.
1046 void JvmtiDeferredEventQueue::process_pending_events() {
1047 assert(Service_lock->owned_by_self(), "Must own Service_lock");
1048
1049 if (_pending_list != NULL) {
1050 QueueNode* head =
1051 (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list);
1052
1053 assert((_queue_head == NULL) == (_queue_tail == NULL),
1054 "Inconsistent queue markers");
1055
1056 if (head != NULL) {
1057 // Since we've treated the pending list as a stack (with newer
1058 // events at the beginning), we need to join the bottom of the stack
1059 // with the 'tail' of the queue in order to get the events in the
1060 // right order. We do this by reversing the pending list and appending
1061 // it to the queue.
1062
1063 QueueNode* new_tail = head;
1064 QueueNode* new_head = NULL;
1065
1066 // This reverses the list
1067 QueueNode* prev = new_tail;
1068 QueueNode* node = new_tail->next();
1069 new_tail->set_next(NULL);
1070 while (node != NULL) {
1071 QueueNode* next = node->next();
1072 node->set_next(prev);
1073 prev = node;
1074 node = next;
1075 }
1076 new_head = prev;
1077
1078 // Now append the new list to the queue
1079 if (_queue_tail != NULL) {
1080 _queue_tail->set_next(new_head);
1081 } else { // _queue_head == NULL
1082 _queue_head = new_head;
1083 }
1084 _queue_tail = new_tail;
1085 }
1086 }
1087 }